1. Field of the Invention
The present invention relates to a heat sink and a method for making the same, and particularly to a reliable heat sink with enhanced heat dissipating effectiveness and a method for making the same.
2. Description of Prior Art
As chips such as microprocessors contain more circuitry and operate at faster speeds, greater amounts of heat are generated, which must be effectively and timely dissipated, otherwise a malfunction or operational instability of the computer will result. Conventionally, a heat sink made from a heat conductive material, such as aluminum, is commonly used to remove the heat generated by a heat generating component, such as a CPU (central processing unit) or a chip in a computer. The heat sink is retained in direct contact with the heat generating component to dissipate the heat into the surrounding environment.
U.S. Pat. No. 5,038,858 discloses a conventional heat sink having a plurality of fins upwardly extending from a base plate thereof. The base plate is retained in direct contact with an upper surface of a chip to dissipate the heat into the surrounding environment via the fins. The fins are attached to the base plate by engaging with parallel grooves defined in the base plate. However, due to gaps inevitably defined between the fins and the base plate, the heat generated by the chip can not be effectively transmitted from the base plate to the fins, thereby significantly degrading the heat dissipating capability of the heat sink.
To overcome the above-mentioned problem, U.S. Pat. No. 5,625,229 discloses a heat sink which comprises a base plate and a corrugated heat dissipating member made of a thin metal. The heat dissipating member includes a repeated series of side wall portions, top walls and connecting portions. The heat dissipating member and the base plate are integrated with each other by bonding the connecting portions of the heat dissipating member with the base plate. Although no gap exists between the heat dissipating member and the base plate, the heat dissipating member and the base plate may separate from each other if the bond fails. In addition, since the adhesive is a material having poor heat conducting capability, the heat dissipating effectiveness of the heat sink is also degraded.
Therefore, an improved heat sink is desired which has fins and a base plate securely attached together thereby enhancing the heat dissipating effectiveness of the heat sink.